Well, if you're outside the discount period allowed, it is now a no-brainer to register an appeal with London Tribnals, because the penalty remains the same, and there are no additional costs at all. If you lose, you pay the full PCN penalty, and if you win, you pay nothing. The council, however have the PITA of preparing an evidence pack and must also pay the adjudication fee. So even if they win, they never get the full amount.